Twelve mayoral candidates means 12 messages, 12 agendas, and 12 visions of how to move Boston forward. And for voters, parsing the chatter to determine who wins their vote has been a hand-wringing experience for many, and for some, it might just come down to a gut feeling or a handshake.

Thoughtful research — and lots of it — helped Karley Ausiello come up with a short list of three candidates: John F. Barros and City Councilors Rob Consalvo and Felix G. Arroyo. First, she thought about the issues that mattered most to her: education and neighborhood affordability. She scoured blogs and read transcripts from forums. But, ultimately, she had to go with “the people who just resonated with me.”

And with a short list created, Ausiello began the process of trying to whittle it down even more. She, her husband, and several other couples gathered “to discuss it over wine.” And the couple also attended a house party, a more intimate setting, where candidates move beyond platitudes and sound bites and small groups of voters demand detailed answers to questions.

As her kindergartner watched a movie in the back and her 13-month-old ran around the living room, shrieking with delight, Ausiello waited for Barros to arrive at a recent house party in a downtown condo. Ausiello lives in Jamaica Plain and said she fears that her neighborhood’s demographics, and those of her daughter’s public school, are changing — and not for the better.

“There’s a house that got listed on my street for $650,000, which to me is astronomical,” she said. Her neighborhood, and her daughter’s school, are becoming less racially diverse, which she said was a matter of concern.

‘You’re not really getting a chance to find out what the candidates are all about.’

For voters like 38-year-old Michelle Caldeira, there are just too many candidates to pick from. At first, she was excited about a field stuffed with “so many significant candidates.” But after attending more than a dozen forums, she said, their messages melded into a cacophony of stump speeches with no distinguishing message.

“You’re not really getting a chance to find out what the candidates are all about,” she said, noting that with 12 candidates, there simply isn’t time in most forums to allow each one to talk in detail about any one issue.

So she has sought smaller venues and house parties, and when she jogged with the Dorchester Swarm, a running group whose members discuss city issues — education, planning, development — Consalvo crisscrossed the neighborhood with them. (Four other candidates ran with the Swarm as well.) And still, she said last week, “I’m totally undecided.”

The problem is that she doesn’t want to cast her vote for someone who can’t win. But she’s still not convinced that those who appear to be narrowly ahead in the polls care about the same things she does: extending the T’s hours of operation, affordable housing, making Boston easier for young professionals to break into.

“People say, ‘Oh, I have all these ideas.’ But tell me, how are you going to get a mass of people to vote for you so you can implement them?” she wonders.

But by Monday night, she’d reached a conclusion: Barros will get her vote.

Candidates have tried in earnest to get voters’ attention through television commercials and radio ads. Cars, trucks, and at least one plane were transformed into moving billboards. Campaign literature was dropped on doorsteps and crammed into mailboxes. And, of course, there were campaign signs on street corner after street corner and lawn after lawn.

But try as candidates might, large chunks of the electorate remained unswayed for much of the campaign during the preliminary election. Polls indicated that nearly 20 percent of voters were undecided as of last week, and candidates were still being told on Sunday: It’s between you and another guy, or girl.

Just whittling it down to a short list was a process. There were homes split between decision and indecision, with one spouse squarely in the court of candidate X and trying to nudge the other in that direction. Some folks have personal connections to candidates, especially those who represented their neighborhoods on the City Council for years, but even that wasn’t enough to seal the deal in some instances.

Michael P. Ross has served as Laura Tomasetti’s city councilor for years, and she thinks he has done great things for the Beacon Hill/West End/downtown area. But, she said, “The field is just really impressive.”

She and her husband, David Beardsley, have been reading the newspaper, trying to get as much information as possible about the candidates, and they think John R. Connolly is a strong candidate, too.

“Those are our top two,” she said last week in Beacon Hill, where she hoped to hear Ross say something that would tip the scales at a meet-and-greet. But she got there just as he was wrapping up and heading to another campaign event. “They are both really behind education in the city. We would have considered a public school in this neighborhood if there was one.”

For some voters, though, the process of elimination will be handled not by them but others who actually cast ballots Tuesday, when voters select the two candidates who will make it into the Nov. 5 final. “I’m going to hold my tongue until after the September vote,” 70-year-old Charles Jones told his friends recently while sitting at the McDonald’s at the Washington Street Mall in Roxbury. “The deal ain’t real until you have two people.”

That should happen Tuesday, as the time has come for voters to step into the ballot box and pick just one name.

“I think I’ve decided,” Ausiello said Monday evening. “I think I’m going for Consalvo. But I still kind of have a holdout. I want to go back and look at Barros and Arroyo.”

Ultimately, she said, the decision will come down to gut instinct supported by research, and it will be made as she fills in the bubble on the ballot.

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